This revealed that GuestDefaultEmulator was a bit buggy, capable
of returning an emulator that didn't match the passed domain type. Fix
up the test suite input to continue to pass.
This is a helper function to look up all capabilities data for all
the OS bits that are relevant to <domain>. This is
- os type
- arch
- domain type
- emulator
- machine type
This will be used to replace several functions in later commits.
According to docs, using 'lun' as a value for device attribute is only valid
with disk types 'block' and 'network'. However current RNG schema also allows
a combination type='file' device='lun' which results in a successfull
xml validation, but fails at qemuBuildCommandLine.
Besides fixing the RNG schema, this patch also adds a qemuxml2argvtest
for this case.
https://bugzilla.redhat.com/show_bug.cgi?id=1210669
Currently, when constructing traffic shaping rules, the ingress
filter is created without any priority specified on the command
line. This makes kernel to make up one. While this works, it
simplifies things a bit if we provide the filter priority. In
this case, since it's the root filter lets give it the highest
priority of number 1.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Add support for HVM direct kernel boot in libxl. Also add a
test to verify domXML <-> native conversions.
Signed-off-by: Chunyan Liu <cyliu@suse.com>
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
In xl config, hvmloader is implied for hvm guests. It is not
specified with the "kernel" option like xm config. The "kernel"
option, along with "ramdisk" and "extra", is used for HVM direct
kernel boot. Instead of using "kernel" option to populate
virDomainDef object's os.loader->path, use hvmloader discovered
when gathering capabilities.
This change required fixing initialization of capabilities in
the test utils and removing 'kernel = "/usr/lib/xen/boot/hvmloader"'
from the test config files.
xl and xm differ a bit in how <os> configuration is represented.
E.g. xl config supports <os><nvram .../></os> via its "bios"
setting.
Move the xenParseOS and xenFormatOS functions from xen_common.c
and copy to xen_xl.c and xen_xm.c so they can be customized for
xm vs xl config. An unfortunate fallout is reordering of entries
in the test config files.
The <inbound/> element to <bandwidth/> has several attributes from
which two are mandatory. Well, from two at least one has to be
present: @average or @floor or both. Instead of inventing crazy RNG
schema, let's make all the attributes optional there and rely on our
parsing code to correctly handle the situation.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
gcc 4.1.2 (hello RHEL 5) on 32-bit platforms complains:
vircgrouptest.c: In function 'testCgroupGetPercpuStats':
vircgrouptest.c:627: warning: integer constant is too large for 'long' type
vircgrouptest.c:628: warning: this decimal constant is unsigned only in ISO C90
vircgrouptest.c:634: warning: integer constant is too large for 'long' type
vircgrouptest.c:635: warning: this decimal constant is unsigned only in ISO C90
vircgrouptest.c:636: warning: this decimal constant is unsigned only in ISO C90
vircgrouptest.c:644: warning: integer constant is too large for 'long' type
* tests/vircgrouptest.c (testCgroupGetPercpuStats): Use ULL suffix.
Signed-off-by: Eric Blake <eblake@redhat.com>
Add virStringHasControlChars that checks if the string has
any control characters other than \t\r\n,
and virStringStripControlChars that removes them in-place.
In one of my previous commits (49ed6cff9) I've introduced a test
among with some files stored under virnetdevtestdata folder.
While this works perfectly within a git tree, the folder was not
getting into .tar.gz and therefore the dist-check would fail.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This patch adds checks for empty bitmaps right after the calls of
virBitmapParse. These only include spots where set API's are called and
where domain's XML is parsed.
Also, it partially reverts commit 983f5a which added a check for
invalid nodeset "0,^0" into virBitmapParse function. This change broke
the logic, as an empty bitmap should not cause an error.
https://bugzilla.redhat.com/show_bug.cgi?id=1210545
rfc3986 states that the separator in URI path is a single slash.
Multiple slashes may potentially lead to different resources and thus we
should not remove them.
This new internal API checks if given CGroup controller is
available. It is going to be needed later when we need to make a
decision whether pin domain memory onto NUMA nodes using cpuset
CGroup controller or using numa_set_membind().
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Commit cd5dc30 added this test, but it fails if
LIBXL_HAVE_BUILDINFO_USBDEVICE_LIST is not defined:
6) Xen XM-2-XML Format fullvirt-multiusb
... libvirt: error : unsupported configuration: multiple USB
devices not supported
FAILED
Instead of always using controller 0 and incrementing port number,
respect the maximum port numbers of controllers and use all of them.
Ports for virtio consoles are quietly reserved, but not formatted
(neither in XML nor on QEMU command line).
Also rejects duplicate virtio-serial addresses.
https://bugzilla.redhat.com/show_bug.cgi?id=890606https://bugzilla.redhat.com/show_bug.cgi?id=1076708
Test changes:
* virtio-auto.args
Filling out the port when just the controller is specified.
switched from using
maxport + 1
to:
first free port on the controller
* virtio-autoassign.args
Filling out the address when no <address> is specified.
Started using all the controllers instead of 0, also discards
the bus value.
* xml -> xml output of virtio-auto
The port assignment is no longer done as a part of XML parsing,
so the unspecified values stay 0.
The 7c3c7f217e and f5c2d6 commits introduced a nodeinfo test.
In order to do that, some parts of sysfs had to be copied.
However, sysfs is full of symlinks, so during copying some
symlinks broke. Remove them, as on different systems they can
point to different files or be broken. At the same time, we don't
need all files added in those commits. For instance we don't care
about 'uevent' files, 'power' folders, and others.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
In the order of appearance:
* MAX_LISTEN - never used
added by 23ad665c (qemud) and addec57 (lock daemon)
* NEXT_FREE_CLASS_ID - never used, added by 07d1b6b
* virLockError - never used, added by eb8268a4
* OPENVZ_MAX_ARG, CMDBUF_LEN, CMDOP_LEN
unused since the removal of ADD_ARG_LIT in d8b31306
* QEMU_NB_PER_CPU_STAT_PARAM - unused since 897808e
* QEMU_CMD_PROMPT, QEMU_PASSWD_PROMPT - unused since 1dc10a7
* TEST_MODEL_WORDSIZE - unused since c25c18f7
* TEMPDIR - never used, added by 714bef5
* NSIG - workaround around old headers
added by commit 60ed1d2
unused since virExec was moved by commit 02e8691
* DO_TEST_PARSE - never used, added by 9afa006
* DIFF_MSEC, GETTIMEOFDAY - unused since eee6eb6
We need to mock virFileExists to return true for "/dev/kvm" because the
test should not depend on host system.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
On IRC, Hydrar pointed a problem where 'virsh edit' failed on
his domain created through an ISCSI pool managed by virt-manager,
all because the XML included a block device with colons in the
name.
* docs/schemas/basictypes.rng (absFilePath): Add colon as safe.
* tests/qemuxml2argvdata/qemuxml2argv-disk-iscsi.xml: New file.
* tests/qemuxml2argvdata/qemuxml2argv-disk-iscsi.args: Likewise.
* tests/qemuxml2argvtest.c (mymain): Test it.
Signed-off-by: Eric Blake <eblake@redhat.com>
Starting a qemu VM with a memory module that has the base address
specified results in the following error:
error: internal error: early end of file from monitor: possible problem:
2015-03-26T03:45:52.338891Z qemu-kvm: -device pc-dimm,node=0,memdev=memdimm0,
id=dimm0,slot=0,base=4294967296: Property '.base' not found
The correct property name for the base address is 'addr'.
Signed-off-by: Luyao Huang <lhuang@redhat.com>
QEMU 2.3 adds these new models to cover Haswell and Broadwell CPUs with
updated microcode. Luckily, they also reverted former the machine type
specific changes to existing models. And since these changes were never
released, we don't need to hack around them in libvirt.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
Recently we've fixed a bug where the status XML could not be parsed as
the parser used absolute path XPath queries. This test enhancement tests
all XML files used in the qemu-xml-2-xml test as a part of a status XML
snippet to see whether they are parsed correctly. The status XML-2-XML is
currently tested in 223 cases with this patch.
The current auto-indentation buffer code applies indentation only on
complete strings. To allow adding a string containing newlines and
having it properly indented this patch adds virBufferAddStr.
To allow adding more tests, refactor the XML-2-XML test so that the
files are not reloaded always and clarify the control flow.
Result of this changes is that the active and inactive portions of the
XML are tested in separate steps rather than one test step.
Function virQEMUCapsInitGuestFromBinary detect kvm support by testing
whether /dev/kvm exists or whether we pass path to kvmbin. Provide the
path we are testing via kvmbin for testing purpose instead of detecting
presence of /dev/kvm to successfully run the tests on all hosts.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Commit 2360fe5d updated formating of <domain> element but forgot to
update qemucaps2xmldata xml files. In addition the test code was broken
too. Update the xml files and return -1 if testCompareXMLToXML fails
together with indentation fix.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Add support to start qemu instance with 'pc-dimm' device. Thanks to the
refactors we are able to reuse the existing function to determine the
parameters.
This patch adds code that parses and formats configuration for memory
devices.
A simple configuration would be:
<memory model='dimm'>
<target>
<size unit='KiB'>524287</size>
<node>0</node>
</target>
</memory>
A complete configuration of a memory device:
<memory model='dimm'>
<source>
<pagesize unit='KiB'>4096</pagesize>
<nodemask>1-3</nodemask>
</source>
<target>
<size unit='KiB'>524287</size>
<node>1</node>
</target>
</memory>
This patch preemptively forbids use of the <memory> device in individual
drivers so the users are warned right away that the device is not
supported.
To enable memory hotplug the maximum memory size and slot count need to
be specified. As qemu supports now other units than mebibytes when
specifying memory, use the new interface in this case.
Add a XML element that will allow to specify maximum supportable memory
and the count of memory slots to use with memory hotplug.
To avoid possible confusion and misuse of the new element this patch
also explicitly forbids the use of the maxMemory setting in individual
drivers's post parse callbacks. This limitation will be lifted when the
support is implemented.
Lets not give a bad example and check for return values of
virNetwork* APIs called within the test. Even though it's
unlikely that any API will fail, it can happen. We're connected
to the test driver after all, and our API sequence is correct. So
test driver should fail only in case of bug or OOM.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Midonet is an opensource virtual networking that over lays the IP
network between hypervisors. Currently, such networks can be made
with the openvswitch virtualport type.
This patch, defines the schema and documentation that will serve
as basis for the follow up patches that will add support to libvirt
for using Midonet virtual ports for its interfaces. The schema
definition requires that the port profile expresses its interfaceid
as part of the port profile. For that reason, this is part of the
patch too.
Signed-off-by: Antoni Segura Puimedon <toni+libvirt@midokura.com>
By querying the qemu guest agent with the QMP command
"guest-network-get-interfaces" and converting the received JSON
output to structured objects.
Although "ifconfig" is deprecated, IP aliases created by "ifconfig"
are supported by this API. The legacy syntax of an IP alias is:
"<ifname>:<alias-name>". Since we want all aliases to be clubbed
under parent interface, simply stripping ":<alias-name>" suffices.
Note that IP aliases formed by "ip" aren't visible to "ifconfig",
and aliases created by "ip" do not have any specific name. But
we are lucky, as qemu guest agent detects aliases created by both.
src/qemu/qemu_agent.h:
* Define qemuAgentGetInterfaces
src/qemu/qemu_agent.c:
* Implement qemuAgentGetInterface
src/qemu/qemu_driver.c:
* New function qemuGetDHCPInterfaces
* New function qemuDomainInterfaceAddresses
src/remote_protocol-sructs:
* Define new structs
tests/qemuagenttest.c:
* Add new test: testQemuAgentGetInterfaces
Test cases for IP aliases, 0 or multiple ipv4/ipv6 address(es)
Signed-off-by: Nehal J Wani <nehaljw.kkd1@gmail.com>
All the devices we have format their address as its last sub-element, so
let's change memballoon to follow suit. Also adjust RNG to allow any
order of them so 'virsh edit' doesn't shout at us.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Now that the size of guest's memory can be inferred from the NUMA
configuration (if present) make it optional to specify <memory>
explicitly.
To make sure that memory is specified add a check that some form of
memory size was specified. One side effect of this change is that it is
no longer possible to specify 0KiB as memory size for the VM, but I
don't think it would be any useful to do so. (I can imagine embedded
systems without memory, just registers, but that's far from what libvirt
is usually doing).
Forbidding 0 memory for guests also fixes a few corner cases where 0 was
not interpreted correctly and caused failures. (Arguments for numad when
using automatic placement, size of the balloon). This fixes problems
described in https://bugzilla.redhat.com/show_bug.cgi?id=1161461
Test case changes are added to verify that the schema change and code
behave correctly.
Use the NUMA total instead of the configured size both in XML and for
uses in the code once NUMA is enabled for a domain.
One test case change is necessary as the rounding of the individual cell
sizes was not matching the rounding of the total size.
In Xen>=4.3, libxl supports new syntax for USB devices:
usbdevice=[ "DEVICE", "DEVICE", ... ]
Add support for that in xenconfig driver. When only one device is
defined, keep using old syntax for backward compatibility.
Adjust tests for changed options order.
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
So far it's just a structure which happens to have 'Obj' in its
name, but otherwise it not related to virObject at all. No
reference counting, not virObjectLock(), nothing.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Use the new single function instead of calling
qemuMonitorJSONGetBlockStatsInfo and
qemuMonitorJSONGetBlockStatsParamsNumber. This will allow to delete the
functions later while still maintaining coverage.
Add a different version of parser for "info blockstats" that basically
parses the same information as the existing copy of the function.
This will allow us to remove the single device version
qemuMonitorGetBlockStatsInfo in the future.
The new implementation uses few new helpers so it should be more
understandable and provides a test case to verify that it works.
qemu HMP commands sent by libvirt are terminated just by a '\r'. The
fake monitor used in tests wasn't prepared to handle this and the
communication would hang on an attempt to do a HMP conversation.
Add a special case for handling commands separated by \r in case HMP is
used.
Our code supports that for ages. When using a <filterref/> to an
<interface/> several parameters can be passed to the filter. Later,
when building firewall rules, parameters are substituted for their
values. However, our RNG schema allowed only one parameter to be
passed.
Reported-by: Brian Rak <brak@gameservers.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Commit 5aee81a0 introduced a new test for disk-serial. The test fails
on i686 arch because there is no need to add "-cpu qemu32" to command
line. To fix the test update emulator in XML to "/usr/bin/qemu" so we
don't add the "-cpu qemu32" to command while running the test on i686 or
x86_64 host.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
We don't usually do tests purely for one change, but one change was
special because when users will migrate to OVMF/AAVMF, commit 18f9f69b
makes their lives easier by allowing them to interleave <type/> inside
<os/>. It would be nice of us to keep the possibility of them pasting
the loader and nvram elements wherever it is valid, hence this test.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Commit 3e4b783e fixed an issue with RNG schema where this address type
was missing, this commit adds a test for it.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
We have something like pvpanic device. However, in some cases it does
not have any address assigned, in which case we produce this ugly XML
(still valid though):
<devices>
<emulator>/usr/bin/qemu</emulator>
...
<panic>
</panic>
</devices>
Lets format "<panic/>" instead.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
There was a mess in the way how we store unlimited value for memory
limits and how we handled values provided by user. Internally there
were two possible ways how to store unlimited value: as 0 value or as
VIR_DOMAIN_MEMORY_PARAM_UNLIMITED. Because we chose to store memory
limits as unsigned long long, we cannot use -1 to represent unlimited.
It's much easier for us to say that everything greater than
VIR_DOMAIN_MEMORY_PARAM_UNLIMITED means unlimited and leave 0 as valid
value despite that it makes no sense to set limit to 0.
Remove unnecessary function virCompareLimitUlong. The update of test
is to prevent the 0 to be miss-used as unlimited in future.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1146539
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Since the APIs support just one element per namespace and while
modifying an element all duplicates would be removed, let's do this
right away in the post parse callback.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1190590
Adding functionality to libvirt that will allow it
query the ethtool interface for the availability
of certain NIC HW offload features
Here is an example of the feature XML definition:
<device>
<name>net_eth4_90_e2_ba_5e_a5_45</name>
<path>/sys/devices/pci0000:00/0000:00:03.0/0000:08:00.1/net/eth4</path>
<parent>pci_0000_08_00_1</parent>
<capability type='net'>
<interface>eth4</interface>
<address>90:e2:ba:5e:a5:45</address>
<link speed='10000' state='up'/>
<feature name='rx'/>
<feature name='tx'/>
<feature name='sg'/>
<feature name='tso'/>
<feature name='gso'/>
<feature name='gro'/>
<feature name='rxvlan'/>
<feature name='txvlan'/>
<feature name='rxhash'/>
<capability type='80203'/>
</capability>
</device>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
In commit edd1295e1d I've introduced an
XML element that allows to configure state of the network interface
link. Somehow the RNG schema hunk ended up in a weird place in the
network schema definition. Move it to the right place and add a test
case.
Note that the link state is set up via the monitor at VM startup so I
originally didn't think of adding a test case.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1173468
https://bugzilla.redhat.com/show_bug.cgi?id=1142631
This patch resolves a situation where the same "<target dev='$name'...>"
can be used for multiple disks in the domain.
While the $name is "mostly" advisory regarding the expected order that
the disk is added to the domain and not guaranteed to map to the device
name in the guest OS, it still should be unique enough such that other
domblk* type operations can be performed.
Without the patch, the domblklist will list the same Target twice:
$ virsh domblklist $dom
Target Source
------------------------------------------------
sda /var/lib/libvirt/images/file.qcow2
sda /var/lib/libvirt/images/file.img
Additionally, getting domblkstat, domblkerror, domblkinfo, and other block*
type calls will not be able to reference the second target.
Fortunately, hotplug disallows adding a "third" sda value:
$ qemu-img create -f raw /var/lib/libvirt/images/file2.img 10M
$ virsh attach-disk $dom /var/lib/libvirt/images/file2.img sda
error: Failed to attach disk
error: operation failed: target sda already exists
$
BUT, it since 'sdb' doesn't exist one would get the following on the same
hotplug attempt, but changing to use 'sdb' instead of 'sda'
$ virsh attach-disk $dom /var/lib/libvirt/images/file2.img sdb
error: Failed to attach disk
error: internal error: unable to execute QEMU command 'device_add': Duplicate ID 'scsi0-0-1' for device
$
Since we cannot fix this issue at parsing time, the best that can be done so
as to not "lose" a domain is to make the check prior to starting the guest
with the results as follows:
$ virsh start $dom
error: Failed to start domain $dom
error: XML error: target 'sda' duplicated for disk sources '/var/lib/libvirt/images/file.qcow2' and '/var/lib/libvirt/images/file.img'
$
Running 'make check' found a few more instances in the tests where this
duplicated target dev value was being used. These also exhibited some
duplicated 'id=' values (negating the uniqueness argument of aliases) in
the corresponding .args file and of course the *xmlout version of a few
input XML files.
In virStorageVolCreateXML, add VIR_VOL_XML_PARSE_NO_CAPACITY
to the call parsing the XML of the new volume to make the capacity
optional.
If the capacity is omitted, use the capacity of the old volume.
We already do that for values that are less than the original
volume capacity.
Commit f7afeddc added code to report to systemd an array of interface
indexes for all tap devices used by a guest. Unfortunately it not only
didn't add code to report the ifindexes for macvtap interfaces
(interface type='direct') or the tap devices used by type='ethernet',
it ended up sending "-1" as the ifindex for each macvtap or hostdev
interface. This resulted in a failure to start any domain that had a
macvtap or hostdev interface (or actually any type other than
"network" or "bridge").
This patch does the following with the nicindexes array:
1) Modify qemuBuildInterfaceCommandLine() to only fill in the
nicindexes array if given a non-NULL pointer to an array (and modifies
the test jig calls to the function to send NULL). This is because
there are tests in the test suite that have type='ethernet' and still
have an ifname specified, but that device of course doesn't actually
exist on the test system, so attempts to call virNetDevGetIndex() will
fail.
2) Even then, only add an entry to the nicindexes array for
appropriate types, and to do so for all appropriate types ("network",
"bridge", and "direct"), but only if the ifname is known (since that
is required to call virNetDevGetIndex().
Well, not that we are not formatting invalid XML, rather than not as
beautiful as we can:
<cpu mode='host-passthrough'>
</cpu>
If there are no children, let's use the singleton element.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This API joins the following two lines:
char *s = virBufferContentAndReset(buf1);
virBufferAdd(buf2, s, -1);
into one:
virBufferAddBuffer(buf2, buf1);
With one exception: there's no re-indentation applied to @buf1.
The idea is, that in general both can have different indentation
(like the test I'm adding proves)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Since s390 does not support usb the default creation of a usb controller
for a domain should not occur.
Also adjust s390 test cases by removing usb device instances since
usb devices are no longer created by default for s390 the s390
test cases need to be adjusted.
Signed-off-by: Stefan Zimmermann <stzi@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
For historical reasons data regarding NUMA configuration were split
between the CPU definition and numatune. We cannot do anything about the
XML still being split, but we certainly can at least store the relevant
data in one place.
This patch moves the NUMA stuff to the right place.
It's easier to recalculate the number in the one place it's used as
having a separate variable to track it. It will also help with moving
the NUMA code to the separate module.
The mask was stored both as a bitmap and as a string. The string is used
for XML output only. Remove the string, as it can be reconstructed from
the bitmap.
The test change is necessary as the bitmap formatter doesn't "optimize"
using the '^' operator.
Rewrite the function to save a few local variables and reorder the code
to make more sense.
Additionally the ncells_max member of the virCPUDef structure is used
only for tracking allocation when parsing the numa definition, which can
be avoided by switching to VIR_ALLOC_N as the array is not resized
after initial allocation.
The "virDomainGetInfo" will get for running domain only live info and for
offline domain only config info. There was no way how to get config info
for running domain. We will use "vshCPUCountCollect" instead to get the
correct cpu count that we need to pass to "virDomainGetVcpuPinInfo".
Also cleanup some unnecessary variables and checks that are done by
drivers.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1160559
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Not all machine types support all devices, device properties, backends,
etc. So until we create a matrix of [machineType, qemuCaps], lets just
filter out some capabilities before we return them to the consumer
(which is going to make decisions based on them straight away).
Currently, as qemu is unable to tell which capabilities are (not)
enabled for given machine types, it's us who has to hardcode the matrix.
One day maybe the hardcoding will go away and we can create the matrix
dynamically on the fly based on a few monitor calls.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
So, when building the '-numa' command line, the
qemuBuildMemoryBackendStr() function does quite a lot of checks to
chose the best backend, or to check if one is in fact needed. However,
it returned that backend is needed even for this little fella:
<numatune>
<memory mode="strict" nodeset="0,2"/>
</numatune>
This can be guaranteed via CGroups entirely, there's no need to use
memory-backend-ram to let qemu know where to get memory from. Well, as
long as there's no <memnode/> element, which explicitly requires the
backend. Long story short, we wouldn't have to care, as qemu works
either way. However, the problem is migration (as always). Previously,
libvirt would have started qemu with:
-numa node,memory=X
in this case and restricted memory placement in CGroups. Today, libvirt
creates more complicated command line:
-object memory-backend-ram,id=ram-node0,size=X
-numa node,memdev=ram-node0
Again, one wouldn't find anything wrong with these two approaches.
Both work just fine. Unless you try to migrated from the older libvirt
into the newer one. These two approaches are, unfortunately, not
compatible. My suggestion is, in order to allow users to migrate, lets
use the older approach for as long as the newer one is not needed.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
